The invention relates to an apparatus for representing a tactile, that is, touchable character.
The invention is based on the task and object of producing a device, by means of which not only is there made possible a representation of Braille characters, but also a representation of structure, for example, touchable line designs, diagrams and letters and numbers, on a uniformly latticed board which is faced with touch buttons or pins.
This task is solved in accordance with another object of the present invention in the manner that for each touch button there are provided two magnets arranged at least substantially axially behind each other, of which at least one is an electromagnet, which by electrical excitation produce a force in the axial direction of the touch button, which force raises or lowers the touch button by means of a magnet core in accordance with the excitation direction, and that there is coordinated to each touch button, a mechanical, magnetically actuatable locking means acting only thereon.
The magnets permit the touch buttons to be raised by electrical impulses corresponding to the Braille-characeter or structure to be represented, thus to be made touchable, whereby each touch button can be controlled individually and at will, since two magnets are coordinated to each touch button. In the touchable position, each touch button can be held by the locking means coordinated thereto, until the locking means coordinated thereto again releases it for a lowering by means of a clear signal, whereby likewise every touch button can be controlled individually and at will. It is of particular advantage that no energy is consumed for the storage of the input information, since the locking devices lock the coordinated touch buttons mechanically in the touchable position and no energy is required so long as they are not actuated.
By a preferred embodiment, of which it is an object of the present invention to provide, at least the to be actuated parts of the locking device are arranged in the field of the magnets, and by the force exerted on them are moveable between their unlocking position and their locking position. The particular advantage lies in that no additional magnet is necessary for the actuation of the locking device, but rather for this purpose, the two magnets can be used, by means of which the stroke of the touch button is performed in the one and the other direction.
The formation of the locking device is possible in various manners in accordance with the present invention. In an advantageous embodiment form in accordance with another object of the invention, the locking device comprises at least one magnetically actuatable locking body which is moveable arranged in a guide. The track formed by this guide has at least one component which is radial to the direction of movement of the touch button. Further, at least one component of the magnetic field which actuates the locking body runs in the direction of this track. By one such formation of the locking device, the locking bodies can be balls or rollers, thus very simple bodies. One obtains thereby a constructively simple and very reliable operating apparatus.
In accordance with still another embodiment of the invention, the locking device comprises a plurality of locking bodies which are moveable in the guide individually and sequentially each by an impulse excitation of the magnetic field which actuates the locking bodies, wherein then the touch buttons can be locked in various positions of height over the board- or touch- plane in a simpler manner by means of repeated impulse-like control of the magnets. The position corresponds thereby to the number of the locking bodies located in the locking position, which can be arranged there next to one another in the direction of the longitudinal axis of the touch body. By the use of several locking bodies three dimensional representation is made possible. This means that, for example, grey or intermediate values can be reproduced, thus tactile pictures with grey tones can be produced.
By another advantageous embodiment form in accordance with yet another objective of the invention, the locking device comprises at least one magnetically actuatable locking body, which is arranged, in a magnetic field, rotatable about the longitudinal axis of the touch button or an axis parallel thereto, which magnetic field has at least one component acting on the locking body in a tangential direction. For the locking of the touch button and its unlocking one obtains here a rotational moment, which in connection with the force acting on the touch button in the longitudinal direction thereof leads to a combination up or down stroke and rotational movement.
In order not to have to control the correct time expiration of the combination stroke-rotational movement by means of a mechanical guide, which would be disadvantageous on the grounds of space as well as on the grounds of reliability and construction expense, in a preferred embodiment in accordance with another object of the invention, the locking device comprises two locking bodies which are rotatable relative to each other around the longitudinal axis of the touch button or an axis parallel thereto and displaceable in the direction of this axis, of which one of the locking bodies is rigidly connected with the touch button and the other is disposed stationarily. The first locking body is thereby formed as an axial projection with sector shaped cross-section on the end of the magnetic core thereof, which end points away from the touchable end of the touch button, and the second locking body is formed as an axial projection of a stationary magnetic core. Both locking bodies in this embodiment have, in advantageous manner, in peripheral direction next to one another, a part made of magnetic material and a part made of non-magnetic material. Moreover in this case the two locking bodies are arranged in peripheral direction adjacent to one another in the manner such that the parts made of magnetic material lie adjacent to each other. Further, the part made of non-magnetic material of the one locking body is equipped on the side pointing to the other locking body with at least one step reduced in its height. The part of the other locking body, which part is made of non-magnetic material catches in this step in the locking position. The axial movement as well as the rotational movement of the locking bodies is attained thus by the form given to them and the material used for them.
A particular advantage of the invention is to be seen in that it is possible to arrange the touchable buttons in the lattice size of 2.5 mm standardized for purposes of the blind in an arrangement of points, lines or areas, in order to make information accessible to the blind in an economical manner in material and time, whereby the holding force required for the purposes of touching is achieved in sufficient magnitude without energy consumption. Thus the invention permits the production of tactile letters for the blind as well as tactile pictures. By the use of a plurality of locking bodies for each locking device additionally in a particularly simpler manner, besides black-white information also gray tonal values can be converted into the tactile equivalent. When the individual setable buttons are composed int a matrix in the standardized lattice size, a text in Braille-characters and likewise a more or less digitized picture can be reproduced. Thereby each button can be individually controlled by shift registers in the X- and Y- direction of this matrix.